The incidence of disability will play a pivotal role in determining the needs of the growing older population in the United States. Following recent research on the disablement process, this project examines the process of environmental adjustment to fimctional limitations among mature adults in order to illuminate the social processes that create or prevent disability. Specifically, the project focuses on residential mobility and changes in living arrangements as responses to declines in physical, cognitive, emotional and social functioning. Because dwelling and community characteristics are a central part of the adjustment process, the project includes dwelling characteristics such as stairs and adaptations for special needs, and community characteristics, such as the presence and extent of local health services for elders, as well as individual characteristics in models of living arrangements and residential mobility. Data are drawn from the two major new data sets, the Health and Retirement Survey (HRS) and the Survey of Asset and Health Dynamics Among the Oldest Old (AHEAD). The investigators will work with the HRS and AHEAD research and survey staff to code county of residence at each interview for all respondents, which has not yet been done for these data. County characteristics for the appropriate years, developed by the investigators from a variety of sources including the 1990 Census and the 1995 Area Resource File, will be affached to the records of each HRS and AHEAD respondent. Measures of fiinctioning of individuals, characteristics of housing, and kin availability will be created. Finally, the investigators will conduct preliminary analyses of the impact of dwelling and local area characteristics on changes in residence and living arrangements among respondents, given their functioning across a number of separate dimensions.